Aspects
Mercury square Mars puts the two 90 degrees apart. Mercury governs thinking, speaking and learning, Mars governs drive, anger and desire, and the pairing is about thinking and acting, and specifically how fast the gap between them closes. Here is what the angle does to it.
An aspect is simply the angle between two planets, and the angle is the relationship. Astrologers read 90 degrees the same way whether it turns up between these two planets or any others, which is why the logic here is checkable rather than asserted.
Mercury is the need to understand and explain. Mars is the need to act on it. Those are different jobs, and in a chart they are done by different parts of a person at the same time.
The subject of this particular pairing is thinking and acting, and specifically how fast the gap between them closes. That is true of any aspect between these two; what changes with the angle is whether the two drives cooperate, ignore each other or collide.
Squares produce movement. Two planets at ninety degrees keep interrupting each other, and that friction is what makes a person develop. Most genuine competence in a chart comes from a square somewhere.
The cost: It is uncomfortable, repeatedly, and the discomfort does not resolve into anything neat. This is an argument you have with yourself for decades rather than a problem you solve once.
Aspects are not on or off. They have an orb, which is how far from exact the angle can be and still count. For squares the usual working orb is up to about 7 degrees, and the closer to exact, the louder the aspect.
| Distance from exact | How much it shows | In practice |
|---|---|---|
| Under 1 degree | Dominant | One of the defining features of the chart. Other people notice it before you explain anything. |
| 1 to 3 degrees | Strong | Clearly present and recognisable in the description above. |
| 3 to 6 degrees | Present | Real but not loud. Usually recognisable once pointed out. |
| Beyond 7 degrees | Not counted | Outside the working orb. Astrologers would not read it. |
The hard aspects have a reputation they do not deserve. Squares produce friction, and friction is where development comes from: almost every genuinely capable person has several, and charts made entirely of easy aspects tend to belong to people who never had to build anything. What a square predicts is effort, not misfortune.
The honest summary is that an aspect tells you where the energy goes, not whether your life will be easy. Both kinds are needed, and most charts have plenty of each.
Not for the aspect itself. Mercury and Mars both move slowly enough that the angle between them barely changes across a single day, so this aspect is reliable from your birth date alone. What you do need a birth time for is the houses the two planets sit in, which is what turns the aspect from a trait into a part of your life.
The same pair at a different angle is the quickest comparison worth making: Mercury trine Mars and Mercury opposition Mars describe the same two drives getting along and grinding, which is the clearest way to see what the planets themselves are doing underneath the angle.
How close an aspect has to be to count matters more here than most people expect: one degree from exact does several times the work of six. And an aspect is often one side of a larger shape, which the aspect patterns page covers.
The two planets are 90 degrees apart in the chart. Mercury governs thinking, speaking and learning and Mars governs drive, anger and desire, so the aspect is about thinking and acting, and specifically how fast the gap between them closes, with two needs that keep interrupting each other.
It is a hard aspect, which means friction rather than misfortune. Hard aspects are where most development in a chart comes from. The cost is that it is uncomfortable, repeatedly, and the discomfort does not resolve into anything neat. This is an argument you have with yourself for decades rather than a problem you solve once.
The usual working orb for a square is up to about 7 degrees. Under a degree it is one of the defining features of the chart; beyond the orb astrologers would not read it at all.
Not for the aspect itself, since both planets move slowly. You do need one for the houses they fall in.
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Planets in HousesMercury in the second house puts thinking, speaking and learning into the department of money and values. Here is what it does, where it strains, and which sign that means for your rising sign.
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AspectsSun square Mars puts the two 90 degrees apart. Sun governs identity and purpose, Mars governs drive, anger and desire, and the pairing is about identity and drive, which is the engine of a chart and the source of most of its energy or most of its frustration. Here is what the angle does to it.
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